As used by hackers, this never refers to niceties about the proper
form for addressing letters to the Papal Nuncio or the order in which one
should use the forks in a Russian-style place setting; hackers don't care
about such things. It is used instead to describe any set of rules that
allow different machines or pieces of software to coordinate with each
other without ambiguity. So, for example, it does include niceties about
the proper form for addressing packets on a network or the order in which
one should use the forks in the Dining Philosophers Problem. It implies
that there is some common message format and an accepted set of primitives
or commands that all parties involved understand, and that transactions
among them follow predictable logical sequences. See also
handshaking,
do protocol.